At present, as one type of tools for improving walking of passengers between floors or for shortening a walking distance of passengers, passenger transportation devices are very common in daily life. As one example, escalators usually used between floors of commercial buildings and moving walks usually used in large airports are especially common. Furthermore, in consideration of device arrangement space, walking distance and the like, a passenger transportation system having a plurality of passenger transportation devices used in series may be set up as well.
In regard to such system, since the application scope and use population thereof are very wide, various problems of potential safety hazards may inevitably and easily happen during use. As one situation, when a certain passenger transportation device in this passenger transportation system is stopped suddenly due to a fault, since an upstream passenger transportation device thereof is still in a control logic of normal operation, it is very possible to cause situations such as passengers on the upstream passenger transportation device and passengers stagnated on the faulted passenger transportation device are gathered, which probably causes safety incidents such as stampede or collision, and mass casualty incidents are even possibly caused under more serious situations. How to improve the safety startup and shutdown control of the plurality of passenger transportation devices in such passenger transportation system becomes a technical problem which needs to be urgently solved in this field.